1. Field of the Invention
The present invention relates generally to an antenna assembly, and more particularly to a dual-band antenna assembly used for wireless local area network (WLAN).
2. Description of the Prior Art
In recent years, Wireless Local Area Network (WLAN) products applying with IEEE 802.11a/b/g standards, such as WLAN cards for computers are gaining popularity in wireless communication market. IEEE 802.11b/g standard is suitable for working at 2.4–2.5 GHz frequency band, while IEEE 802.11a standard is suitable for working at 5–6 GHz frequency band. Many of the WLAN products are wanted to be used under both IEEE 802.11a and IEEE 802.11b/g standard benefit from dual-band antennas.
For achieving dual-band effect, a dual-band dipole antenna is one of the most mature dual-band antennas in both design and manufacture.
A conventional dual-band dipole antenna is disclosed in U.S. Patent Application No. 2004/0080464 by Suganthan et al. Suganthan et al. discloses a printed dual-band dipole antenna comprising a substrate having a main surface and a first and a second dipoles forming on the main surface. The radiating portion of the first dipole and that of the second dipole are connected with each other. The ground portion of the first dipole and that of the second dipole are connected with each other. Therefore, for feeding the two dipoles, only one feed cable needs to be used. This conventional dual-band dipole antenna has a simple structure. However, when transmitting high-frequency signals under a lower power, this antenna exposes disadvantages of dissatisfactory low gain and narrow bandwidth.
Hence, in this art, a high gain dual-band antenna assembly to overcome the above-mentioned disadvantages of the prior art will be described in detail in the following embodiment.